1. Field of the Invention
The present invention relates to a high quality electrophotographic image receiving sheet having a combination of excellent toner fixation, high adhesion resistance and reliable transport qualities, and an electrophotographic image forming method for use with the electrophotographic image receiving sheet.
2. Description of Related Art
Electrophotography has been widely used as output equipments such as copying machines and printers for use with personal computers on the grounds of printing out on general-purpose paper such as plain paper and bond paper at a high printing speed in a dry process. Electrophotographic image receiving sheets for use in the electrophotographic printing has a toner image receiving layer. This toner image receiving layer can be formed in various processes, for example, such as a process of laminating a thermoplastic resin on a support sheet made of base paper by means of melt extrusion or a process of coating the support sheet with a liquid solution of resin. Thermoplastic resins that are ordinary employed for the toner image receiving layer are amorphous polymers having glass-transition temperatures (Tg) in a range of from a temperature higher than the ambient temperature to a temperature several tens of degrees in centigrade below a potential toner fixing temperature. However, the amorphous polymers are excellent in adhesion to toner and, at the same time, apt to cause adhering trouble between the toner image receiving layers due to their high adhesion strength.
On the contrary, since crystalline polymers even having glass-transition temperatures (Tg) in a range of subzero temperatures are soft in adhesion at ambient temperatures, they do not cause adhering troubles between the toner image receiving layers, nevertheless there is a problem that fixed toner falls away from the toner image receiving later due to insufficient adhesion strength of the crystalline polymer.
As just described, the polymers, amorphous or crystalline, have their inherent defects crying out for solutions. U.S. Pat. No. 5,104,721 discloses an electrophotographic printing media that contain a crystalline polymeric pigment in an image receiving layer comprising an amorphous polymer in major proportion polymeric as one of the solutions. However, the pigment, that is added as a matting agent with the intention of adjusting a coefficient of dynamic friction, is particulate matter and poor in compatibility with amorphous polymeric materials.